We propose to develop a web & cell phone-based weight control intervention that physicians can offer their overweight post-partum patients: PACEi-MoM. The intervention will target women classified as overweight to Level 1 Obese (BMIof 25 -34.9 NIH,1998) at 4 to 8 weeks post-delivery who are able to do moderate ntensity physical activity such as walking. We will involve recent mothers and providers of obstetrical care in 3ACE-MoM formative research. Behaviors specifically targeted include: decreasing dietary fat intake; ncreasing fruit, vegetable and fiber intake; and increasing overall physical activity.iMoMwill be based on empirically supported approaches to health behavior change that SDCHI researchers have been evaluating or several years, and thoroughly informed by focus groups with recent mothers and providers of obstetrical care. The iMoM product will be a 12-month online program with integrated cell phone messaging and uploadable pedometer components, to help new mothers reach and maintain a healthful weight. Topics, program architecture, graphics and user interface development will be informed by two focus groups with post partum mothers, one focus group with obstetrical care providers, usability testing with post partum mothers, and ongoing input from two obstetric care consultants. PACEi-MoM is particularly innovative because: 1) It addresses needs of a population at risk for continued weight gain, at a key transitional time that is characterized by destabilization of former health behaviors and new, demanding barriers. 2) It meets a special need for long-term, evidence-based, and comprehensive behavioral weight management approaches tailored to new mothers, 3) It utilizes cell phone text messaging as an important intervention modality for busy mothers, in the form of prompts about specific behavioral goals and as a reinforcerof overall program compliance and 4) It utilizes a high-quality pedometer with a featureof convenient, automatic data uploading to the PACEi-MoM web site, via the user's home PC and proprietary software. This formative research will enable the creation of the PACEi-MoM.product, to be studied for effectiveness in Phase II.